1. Field of Invention
The current invention relates to security tags and more particularly, discloses a blister pack that comprises an EAS or RFID coil or antenna as part of the metal layer (e.g., aluminum) seal and to which a capacitor strap or chip strap can be electrically coupled to form the EAS or RFID security tag.
2. Description of Related Art
Tracking or detecting the presence or removal of retail items from an inventory or retail establishment comes under the venue of electronic article surveillance (EAS), which also now includes radio frequency identification (RFID). EAS or RFID detection is typically achieved by applying an EAS or RFID security tag to the item or its packaging and when these security tags are exposed to a predetermined electromagnetic field (e.g., pedestals located at a retail establishment exit), they activate to provide some type of alert and/or supply data to a receiver or other detector.
However, the application of the EAS or RFID security tag to the item or its packaging in the first instance can be expensive and wasteful of resources used to form the security tag. For example, EAS security tags, typically comprise a resonant circuit that utilize at least one coil and at least one capacitor that operate to resonate when exposed to a predetermined electromagnetic field (e.g., 8.2 MHz) to which the EAS tag is exposed. By way of example only, the coil and the capacitor are etched on a substrate whereby a multi-turn conductive trace (thereby forming the coil) terminates in a conductive trace pad which forms one plate of the capacitor. On the opposite side of the substrate another conductive trace pad is etched to form the second capacitor plate, while an electrical connection is made through the substrate from this second plate to the other end of the coil on the first side of the substrate; the non-conductive substrate then acts as a dielectric between the two conductive trace pads to form the capacitor. Thus, a resonant circuit is formed. Various different resonant tag products are commercially available and described in issued patents, for example, U.S. Pat. Nos. 5,172,461; 5,108,822; 4,835,524; 4,658,264; and 4,567,473 all describe and disclose electrical surveillance tag structures. However, such products utilize, and indeed require, substrates which use patterned sides of conductive material on both face surfaces of the substrate for proper operation. Special conductive structures and manufacturing techniques must be utilized on both substrate faces for producing such resonant tag products. Currently available EAS tag structures have numerous drawbacks. For example, since special patterning and etching techniques must be utilized on both sides of the available tags to produce the proper circuit, per unit processing time and costs are increased. Furthermore, the complexity of the manufacturing machinery required for production is also increased. Oftentimes, complex photo-etching processes are used to form the circuit structures. As may be appreciated, two sided photo-etching is generally time consuming and requires precise alignment of the patterns on both sides. Additional material is also necessary to pattern both sides, thus increasing the per unit material costs.
With particular regard to radio frequency identification (RFID) tags, RFID tags include an integrated circuit (IC) coupled to a resonant circuit as mentioned previously or coupled to an antenna (e.g., a dipole) which emits an information signal in response to a predetermined electromagnetic field (e.g., 13.56 MHz). Recently, the attachment of the IC has been accomplished by electrically-coupling conductive flanges to respective IC contacts to form a “chip strap.” This chip strap is then electrically coupled to the resonant circuit or antenna. See for example U.S. Pat. Nos. 6,940,408 (Ferguson, et al.); 6,665,193 (Chung, et al.); 6,181,287 (Beigel); and 6,100,804 (Brady, et al.).
Applying such EAS or RFID security tags to pharmaceutical blister packs is challenging because of the blister pack construction. A typical pharmaceutical blister pack comprises pills, tablets, or capsules that are positioned inside a plastic or paper tray which is then heat sealed with an aluminum layer. The presence of the aluminum layer can affect EAS or RFID security tag performance. Thus, there remains a need for more efficiently providing or integrating a security tag on or with items and/or their packaging where an aluminum layer is associated with the item and/or its packaging.
All references cited herein are incorporated herein by reference in their entireties.